With respect to their position relative to the clavicula, the rami of the plexus brachialis can be divided into rami supraclaviculares and rami infraclaviculares. The rr. supraclaviculares include the n. dorsalis scapulae, n. suprascapularis, n. thoracicus longus and n. subclavius. The rr. infrascapulares can be further divided into rr. preterminales and rr. terminales. The rr. preterminales infraclaviculares emerge from the fasciculus lateralis, fasciculus medialis and fasciculus posterior. The fasciculus lateralis gives rise to the n. pectoralis lateralis. The fasciculus medialis gives rise to n. pectoralis medialis, n. cutaneus medialis brachii, n. cutaneus medialis antebrachii. The fasciculus posterior gives off the n. subscapularis superior, n. subscapularis inferior, n. thoracodorsalis. Finally, the five main rr. terminales include the n. musculocutaneous, n. axillaris, n. medianus, n. radialis and n. ulnaris.
